凯威特球面巨型网格结构静力性能与地震响应研究

发布时间：2018-06-23 08:19

本文选题：凯威特球面巨型网格结构 + 静力性能　；参考：《西安建筑科技大学》2014年硕士论文

【摘要】：基于巨型网格结构概念与球面网壳结构的力学性能，本文提出了一种新型结构——凯威特球面巨型网格结构，该结构的网格大小均匀、重量轻、刚度大、外型美观，适合于功能性较强的大跨度结构，具有广阔的应用前景。本文借助于大型通用有限元软件Ansys建立了凯威特球面巨型网格结构有限元模型,分析了结构的基本静力性能，，探讨了结构的矢跨比、跨度、立体桁架高度因子和支承方式等参数对径向桁架上下弦杆应力分布规律的影响。在考虑初始几何缺陷和几何非线性的情况下，利用牛顿-拉夫逊法分析结构的弹性稳定性能，研究了结构的矢跨比和支承方式对结构弹性极限承载力的影响，计算结构的平均应力比，确定导致结构破坏的主要因素。分析了凯威特球面巨型网格结构自振频率的分布规律和各阶振型的振动形式。研究了结构的矢跨比、跨度、桁架高度因子等参数对结构自振特性的影响。利用时程分析法对凯威特球面巨型网格结构进行了动力响应研究，得到了径向桁架上下弦杆的应力分布规律和上下弦节点位移的分布规律，并对不同地震波作用下的动力响应进行了对比分析。研究表明：矢跨比、跨度和支承方式是影响凯威特球面巨型网格结构应力分布和自振特性的主要结构参数，结构矢跨比宜取0.25，支承方式宜采用上下弦固定铰接；凯威特球面巨型网格结构具有良好的稳定性和抗震性能，结构的破坏主要由强度控制，结构杆件应力和节点位移主要由静力条件控制；子结构参与承载可显著降低杆件的应力值。研究结论为凯威特球面巨型网格结构的工程应用提供了理论基础和设计依据。
[Abstract]:Based on the mega grid structure concept and the mechanical properties of the spherical reticulated shell structure, this paper presents a new structure, the gigantic spherical Mega grid structure. The structure is uniform in size, light in weight, large in stiffness, and beautiful in external shape. It is suitable for large span structures with strong functions and has a broad application prospect.
In this paper, the finite element model of the gigantic spherical Mega grid structure is established by the large general-purpose finite element software Ansys. The basic static properties of the structure are analyzed. The effects of the parameters of the structure, such as the span ratio, the span, the height factor of the truss and the supporting mode, on the stress distribution of the upper and lower chords of the radial truss are discussed. Under the condition of the defects and geometric nonlinearity, the Newton Raphson method is used to analyze the elastic stability of the structure. The influence of the structure's span ratio and the supporting mode on the elastic ultimate bearing capacity of the structure is studied, and the average stress ratio of the structure is calculated, and the main factors that lead to the structural damage are determined.
The distribution law of the free vibration frequency of the gigantic spherical Mega grid structure and the vibration modes of each order are analyzed. The influence of the parameters of the structure, such as the span ratio, the span and the height factor of the truss, on the self vibration characteristics of the structure are studied. The dynamic response of the structure is studied by the method of time history analysis, and the radial trusses are obtained. The stress distribution law of upper and lower chords and the distribution law of displacement of upper and lower chord nodes are compared, and the dynamic responses under different seismic waves are compared and analyzed.
The results show that the span ratio, span and supporting mode are the main structural parameters that affect the stress distribution and the self vibration characteristics of the gigantic spherical Mega grid structure. The vector span ratio should be 0.25, the supporting mode should be fixed with the upper and lower chords, and the structure has good stability and seismic performance. In order to control the strength of the structural members, the stress and displacement of the structural members are mainly controlled by the static condition, and the stress values of the members can be significantly reduced by the substructure participating in the bearing. The conclusion provides the theoretical basis and the design basis for the engineering application of the giant spherical meshes.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU399;TU311

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